The proposed research aims to increase scientific knowledge concerning the psychological, behavioral, and social responses of police officers to traumatic stress, including exposure to violence, along and in combination with exposure to more routine administrative, managerial, and community relations stressors. A two-group cross-sectional survey and a Clinical Interview Subsample (CIS) design is proposed. The experimental group will consist of 700 police officers drawn from three major urban departments: New York Police Department, Oakland Police Department, and San Jose Police Department. The control group consists of 350 case-control, demographically matched, peer-nominated citizens, not working in police or emergency services professions. The police sample will include 350 patrol officers, 350 detectives, 140 women officers, 140 African American officers, and 140 Hispanic officers. Both groups will complete a two hour self-report questionnaire package to assess lifetime and work-related traumatic stressor exposure, routine work stress exposure, posttraumatic stress symptoms, general psychiatric symptoms, work and interpersonal functioning, physical health, and selected risk and protective factors. The CIS will comprise 200 police equally divided into four groups: high exposure/high PTSD symptom response; high exposure/low PTSD symptom response; low exposure/high PTSD symptom response; and low exposure/low PTSD symptom response. The CIS will be interviewed with the CAPS, the SCID and the DSM-IV field trial trauma history interview, and will complete additional measures of risk and protective factors. The investigators will examine patterns of trauma exposure and response, and their relation to the work environment, in officers and controls. In interviewed officers we will compare survey and interview assessments, determine diagnostic status, and examine risk and reliance, highlighting the roles of lifetime exposure to trauma, personality, beliefs and reactions, general dissociative tendencies, and peritraumatic dissociation.